@misc{indiciaef5959d040616,
  title = {Spatial aggregation in gravity models: 4. Generalisations and large-scale applications.},
  author = {M Batty and P K Sikdar},
  year = {1982},
  doi = {10.1068/a140795},
  url = {https://pubmed.ncbi.nlm.nih.gov/12265202/},
  note = {Source identifier: 12265202}
}